In industries such as semiconductor processing, pharmaceutical and chemical manufacturing, high purity, highly corrosive or highly caustic liquids are utilized. Due to safety and quality considerations, these liquids must be contained in containers and dispensing systems of high reliability and integrity. The connections, tubing, and fittings for handling these fluids must be formed from highly inert materials. Fluoropolymers have been found to be suitable for use in these environments. The tubing can be formed of PFA, the fittings, valve components and dispense heads may be formed of components such as PFA and PTFE, and other fluoropolymers. Containers for handling these liquids are typically plastic drums formed of high purity polyethylene such as those disclosed in U.S. Pat. No. 6,045,000, which is hereby incorporated by reference. The drums will conventionally have a bung opening with a drum insert that includes a down tubing portion connecting to an upward and concentric nipple of the bung. A dispense head couples with the drum insert and has a main fluid passageway that connects to and sealingly engages the nipple for dispensing fluid from the drum.
When transporting or storing the drums, conventional caps or plugs are placed over or in the bung opening of the drum. Various factors can cause pressure to build up within the drum during transportation and storage. These factors can include the type of fluids/materials stored within the drum, the time of storage, altitude and temperature changes, transporting activities, and the like. For instance, ammonia hydroxide and peroxide are commonly stored and transported fluids that often cause pressure to build up in drums. When the cap is eventually removed from a pressurized drum to connect the dispense head to the drum prior to use, gasses or even the stored liquid itself can be discharged out of the bung opening, posing a very serious safety threat to those in proximity of the drum.
Venting systems have been developed in an attempt to address these pressure-related concerns. Namely, various vent connection ports and valves have been added to the drum fittings or drum closures to vent the internal drum pressure. Examples of such systems are disclosed in previously incorporated U.S. Pat. No. 6,045,000. However, such conventional venting techniques do not incorporate the designs and mechanisms required to ensure evacuation or venting of the pressurized gas to a safe area. Accordingly, a storage and transporting drum cap is needed that will address the dangers and concerns inherent with pressure buildup within conventional fluid storage and dispensing drums.